Aim Cost is a major determinant of food purchases. The central question for this PhD is whether healthy eating costs more than less healthy eating. Monitoring the cost of foods, meals and diets is important to provide evidence to inform policies. Each approach needs standardised methodologies to ensure fair comparisons over time, and between countries. Method Standardised methods were developed and piloted to measure the relative costs of healthier and less healthy foods, meals and diets using commonly consumed foods and locally collected prices. The use of different data sources and methodological approaches was explored to assess the impact on cost. Results The foods approach measured the price of foods over time using the WHO Europe nutrient profile model and the NOVA classification (degree of processing), and compared the cost of pairs of healthier and less healthy foods. The meals approach compared the cost of popular takeaway meals with healthier home-cooked meals, incorporating the cost of preparation or waiting time. The diet approach compared the cost of a healthy and a current diet. Healthier and less healthy foods, and minimally processed, processed and ultra-processed foods all increased in price at a similar rate over ten years. The healthier items of a pair tended to cost the same as, or more than, the less healthy counterpart. Healthier home-made and home-assembled meals were less expensive than their takeaway counterparts. When time was included, home-assembled meals were the cheapest option and half the home-made meals were at least as expensive as the takeaway meals. The healthy and current diets were similar in price when only the current diet contained alcohol and takeaways, and the energy requirement of the diets was to maintain the recommended BMI for an active person (healthy diet) or maintain the current BMI at current activity levels. Altering aspects of diet, including or excluding takeaways, and generic labels, and altering the energy requirements had considerable impacts on cost. Conclusion This thesis developed novel methods to provide a simple, standardised approach to monitor the price of healthier and less healthy foods, meals and diets enabling comparisons over time, and between countries.

Cost and affordability of healthy diet (CoAHD) metrics developed in a handful of academic studies have quickly become mainstream food security indicators among major development institutions. The World Bank and FAO now report CoAHD statistics in their widely used databanks, and the UN’s State of Food Insecurity and Nutrition in the World (SOFI) reports CoAHD metrics on an annual basis, with the headline conclusion being that over 3 billion people worldwide cannot afford a healthy diet. While quantifying affordability constraints is indeed a vital addition to the suite of global food security indicators, there is a dearth of scientific analysis on the accuracy and sensitivity of CoAHD methods. Published global CoAHD estimates rely on three implicit assumptions: that demographic differences across countries have little effect on average diet costs; that non-food expenditure requirements have little systematic variation across countries; and that international food price data is representative in a population sense and product coverage sense. Testing these assumptions on the cost of the EAT-Lancet reference diet, we find sizable sensitivity of baseline methods to adjusting diet affordability estimates for systematic cross-country differences in demographic profiles and non-food expenditure requirements, smaller effects of adjusting for inadequate food product coverage in international price data, and inconclusive evidence on issues of urban bias in price surveys. Our proposed methodological improvements significantly change country, regional and global estimates of healthy diet affordability, though not the headline conclusion that several billion people cannot afford a healthy diet. Even so, the accuracy, rigor, and reliability of CoAHD statistics warrant closer investigation given their widespread adoption and utilization.

Price and affordability are key barriers to accessing sufficient, safe, nutritious food to meet dietary needs and food preferences for an active and healthy life. In this study, the least-cost items available in local markets are identified to estimate the cost of three diet types: energy sufficient, nutrient adequate, and healthy (meeting food-based dietary guidelines). For price and availability the World Bank’s International Comparison Program (ICP) dataset is used, which provides food prices in local currency units (LCU) for 680 foods and non-alcoholic beverages in 170 countries in 2017. In addition, country case studies are developed with national food price datasets in United Republic of Tanzania, Malawi, Ethiopia, Ghana and Myanmar. The findings reveal that healthy diets by any definition are far more expensive than the entire international poverty line of USD 1.90, let alone the upper bound portion of the poverty line that can credibly be reserved for food of USD 1.20. The cost of healthy diets exceeds food expenditures in most countries in the Global South. The findings suggest that nutrition education and behaviour change alone will not substantially improve dietary consumption where nutrient adequate and healthy diets, even in their cheapest form, are unaffordable for the majority of the poor. To make healthy diets cheaper, agricultural policies, research, and development need to shift toward a diversity of nutritious foods.

One of the greatest global challenges today is ensuring widespread availability and equitable access to affordable, nutritious foods produced in an environmentally sustainable manner. A rich literature exists around the definition of a healthy diet and the drivers of dietary change. We contribute to this literature by proposing a new quantifiable diet deprivation measure estimated from standard household consumption and expenditure surveys. The Reference Diet Deprivation (ReDD) index measures the incidence, breadth, and depth of diet deprivation across multiple, essential food groups in a single indicator. Although useful as a standalone measure, we show how ReDD can be integrated into an economywide model to examine changes in household diet quality under different simulation scenarios. Using Nigeria as case study, hypothetical agricultural productivity growth scenarios reveal that dairy, pulses, fruit, and red meat value chains have the greatest potential to reduce overall diet deprivation in Nigeria per unit of GDP growth generated, while productivity growth in more widely consumed crops such as cereals and root crops do little to improve diet quality. These findings have implications for the prioritization of agricultural development initiatives aimed at improving the quality of diets. More generally, the integration of a diet quality indicator in an economywide model allows for a deeper understanding of the drivers of dietary change.

Considering the detrimental environmental impact of current food systems, and the concerns raised about their sustainability, there is an urgent need to promote diets that are healthy and have low environmental impacts. These diets also need to be socio-culturally acceptable and economically accessible for all. Acknowledging the existence of diverging views on the concepts of sustainable diets and healthy diets, countries have requested guidance from the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) on what constitutes sustainable healthy diets. These guiding principles take a holistic approach to diets; they consider international nutrition recommendations; the environmental cost of food production and consumption; and the adaptability to local social, cultural and economic contexts. This publication aims to support the efforts of countries as they work to transform food systems to deliver on sustainable healthy diets, contributing to the achievement of the SDGs at country level, especially Goals 1 (No Poverty), 2 (Zero Hunger), 3 (Good Health and Well-Being), 4 (Quality Education), 5 (Gender Equality) and 12 (Responsible Consumption and Production) and 13 (Climate Action).

In the United States, people living in low-income neighborhoods frequently do not have access to affordable healthy food venues, such as supermarkets. Instead, those living in "food deserts" must rely on convenience stores and small neighborhood stores that offer few, if any, healthy food choices, such as fruits and vegetables. The Institute of Medicine (IOM) and National Research Council (NRC) convened a two-day workshop on January 26-27, 2009, to provide input into a Congressionally-mandated food deserts study by the U.S. Department of Agriculture's Economic Research Service. The workshop, summarized in this volume, provided a forum in which to discuss the public health effects of food deserts.

Most Americans consume diets that do not meet Federal dietary recommendations. This perception may be influenced by studies that found healthy foods to cost more per calorie than less healthy foods. This is one way, but not the only way, to measure the cost of a healthy diet. For a balanced assessment, this book compares the price of healthy and less healthy foods using three metrics: the price per calorie, per edible gram, and per average portion. These studies conclude that the higher prices of healthy foods present barriers to consumer ability to buy recommended amounts of foods like fruits and vegetables.

The health and environmental consequences of our dietary choices impose costs on society that are currently not reflected in the price of those foods or diets that contribute to these detrimental impacts. This paper provides updated estimates of two major cost items: the healthcare-related costs associated with unhealthy diets, and the climate-change costs associated with the emissions attributable to diets and food production. Results suggest that the health and climate-change costs of current diets are substantial and projected to increase up to 1.3-1.7 trillion USD annually by 2030.

Although healthy foods can be affordable, if less healthy foods are cheaper, individuals may have an economic incentive to consume a less healthful diet. Using the Quarterly Food-at-Home Price Database, the authors explore whether a select set of healthy foods (whole grains, dark green vegetables, orange vegetables, whole fruit, skim and 1% milk, fruit juice, and bottled water) are more expensive than less healthy alternatives. They find that not all healthy foods are more expensive than less healthy alternatives. They also find considerable geographic variation in the relative price of healthy foods. This price variation may contribute to geographic variation in diet and health outcomes. Charts and tables. This is a print on demand report.